Throttle-valve for pneumatic drills.



A'. LEVEDAHL. THROTTLE VALVE FOR PNEUMATIC DRILLS.

APPLICATION FILED JUNE 1, 1908.

Patented Sept 283909.

To all whom it mag concerns I r UNITE STAES TENT OFFICE.

.axnr. rnvnnant, or annorm, rumors,

ASSIGNOR ,10 AURORA AUTOMATIC Be it known that I, Am Lnvnnann, a citizen of the United States, and a resident of Aurora, 1n the county ofKane and State of Pneumatic Drills;

Illinois, have invented certain new and useful Improvements inThrottle-Valves for and I do hereby declare that the following is afull, clear, and exact dmcription thereof, reference being bad to; theaccom anying" drawings, and to the numerals of reference marked thereon,which.- form a part of this specification. g This invention relates toimprovements in throttle valves of the kind used'in portable pneumatictools, such as pneumatic drills having an air driven motor and providedwith two handles one of whichcontains the throttle-valve mechanism forcontrolling admission of air to the motor, and the invention refers morespecifically to an improved construction and arrangement of the partsassociated with the throttle valve by means of which the. valve isoperated by the hand of the operator which gras s the handle of the tooland is adapted to be automatically v closed when the operatorsgrasp isreleased.

The invention consists in the matters here- 'inafter set forth and moreparticularly pointed out in the appended claims.

In the drawings :Figurel is a side elevati'on of a'tool handlecontaining a throttle- Fig.2.

valve embodying my invention. Fig. 2 is a view in central longitudinalsection taken through'the tool handle, and the throttle valve mechanism.Fig. 3 is a section, on a slightly larger scale, taken upon line 3--3 ofFig. 4 is a section. on a larger scale taken upon line 4. l of Fig. 2.Fig. 5 is a sectional view on a larger scale taken upon line 5-5 of Fig.2. Fig. 6 is a View in side elevation of the endwise sliding cylinder inthe tubular handle. Fig. 7 is a side view of the guide disk for thevalve-stem.

As. shown in said drawings, 1 indicates the tubular handle of the toolin which is contained the throttle valve mechanism and which is graspedby the operator during the time the drill is in operation. Thehandle 1is provided with a bore or passage extend ing through-the same from endto end. Over the portion of the handle 1 which is grasped by theoperator thereis fitted an exteriorly knurled cylindric sleeve forming ahand grip. The throttle valve illustrated 1n the drawings is located inthe bore of the handle 7 Specification of Letters Patent.

7 Application filed June 1, 1908 Serial No. 435,865.

I rnnorrtn-vanvn son PNEUMATIC n'ruLLs.

Patented Sept. 28, 1909.

land adjacent to that portion of the said handle which is surrounded bythe sleeve 2'. v The bore or passage of the handle 1, in which thethrottle valve is located, opens at its ends through both ends ofthehandle', and

one end of the bore constitutes a supply passage or inlet for the air orother fluid under pressure. In said inlet end of the bore or passage isinserted a sleeve or nipple 3 having interior screw threads forattachment thereto of the pipe or hose through which air is supplied tothe tool. Said nipple 3 has external screw-threads engaging thecorresponding -screw-threads in the end of said bore-0r passage which isenlarged to receive it. Within said passage and near the inlet end is alongitudinally arranged valve stem 4 which isprovided with a valve disk5, adapted to bear on a valve seat formed by an inwardly extendingofiset or shoulder 6- handle sotliat the pressure-of the air entering'the bore of the handle tends to press the said valve disk againstits seat, or to hold.

the valve closed. The opposite or inner end.

of the valve stem bears endwise against a cylindric block 7, whichis-adapted to slide endwise in the bore of the tube 1. A cylindricseatis formed in the tube 1 in which the cylindric block 7 fits and slides,andsaid block is provided at its opposite sides with longitudinalgrooves or channels 11, 11 to permit the passage of air through the tubepast mid block. The inner end of said valve stem is provided with aconical point which engages a conical recess in the adjacent end of saidblock.

v The nipple 3 is provided at its inner end with a rigidly attachedguide disk 8 having a guide aperture formed centrally therein, throughwhich passes the adjacent or outer end of the valve stem 4. The saidguide disk 8 is provided with curved slots or apertures 9, 9 formedconcentric with the guide aperture therein and through which air passesto the valve. Between the guide disk 8 and the valve disk 5 is a-coiledactuating spring 10 y which the valve disk is held normally against thevalve seat. a I

Provision is-made for operating the throttle valve for admission of airto the motor as follows: Secured to one side of the said sliding block 7at right angles thereto is an outwardly extending stud 12. Said stud ofan annular shoulder 14 on the tube 1, against which the inner-end of thesleeve abuts, and by contact of the opposite or outer end of 'saidsleeve with an outwardly extending annular flange 15 on the nipple 3.Pivotally supported upon the said sleeve 2,

- bymeans of pivot studs 16, 16, is a hand lever 17 which is providedwith lateral arms 18, 18 extending from the pivoted end of the lever atopposite sides of the sleeve 2, and through which the pivot studs 16, 16are inserted. The opposite or swinging end of said lever 17 extends fromits pivoted end outwardly or toward the inlet end of the 20 tube 1. Atits ivoted end the said lever 17 is provided with an aperture 19 throughwhich the outer end'of the stud 12 extends.

The said aperture 19 is arranged substantially in transverse alinementwith the pivot studs 16, 16; the arrangement of the parts being suchthat when the free end of the lever is pressed toward the tube theaperture therein which engages the stud 12 will be moved or shiftedendwise of the tube and toward its outer or inlet,end, and a likemovement will be transmitted to the sliding block 7 through the mediumof the said stud 12: The said sliding block, by its endwise pressure onthe valve stem, will shift the same endwise against the action of thespring 10 to effect the opening of the valve.

In order that the parts gripped by the hand of the operator may be assmall in diameter as possible, the lever 17 is transversely curved andhas its inner side concave to correspond with the curvature of the,sleeve 2. By this construction in the lever,

- when said lever is pressed a ainst the sleeve 2, it will afford asubstantial y cylindric surface .to be held or gripped by the operatorduring the handling of the tool. The tube or handle 1 at its exit end,or that which is attached to the tool, is shown asprovided with ascrew-threaded nipple 20, by" which it is connected With the casing 01''the tool.

In the operation of the throttle valve described, the hand of theoperator is applied around the sleeve 2 and the lever 17 in such mannerthat, by the asp of the hand, the

= lever is swun inwar ly and the cylinder 7 thereby move longitudinallytoward the inlet end of said handle; A corresponding movement will beimparted to the valve stem 4 and the'vaive disk-5 will be moved againstthe action of the spring 10 and the pressure of the incoming motivefluid or air away The motive fluid or air will then pass through theapertures 9,9 of the guide disk 8, through the o ening in the valveseat, and through the cliannels 11', 11

of the cylinder '7 to the motor. When the operators grip upon the handleis released the valve disk. 5 will be shifted to its closed position bythe action of the spring 10 aided by the air-pressure.

An advantage gained by the construction described is that the throttlevalve will close automatically when the pressure of the hand on thehandle of the tool is released, thereby insuring the stoppage of themotor in case the handle of the tool should slip'from the grasp of theoperator.

It is to be understood that the presence of the sleeve 2 is notnecessary to the operation of the throttle valve described, althou h thesame is of advantage because affor ing a pivotal support for the handlever 17 adapted to be easily placed upon and removed from the .tube 1.In case the said sleeve 2 is omitted, the hand lever 17 will bepivotally connected with the tube 1 in some other convenient manner. Theemployment of sa d sleeve 2,as a separate removable member, is ofadvantage, moreover, because incase a self-closing valve be not desired,the sleeve 2 with the hand-lever may be removed from the tube, and forthe same may be substi- -a throttle valve embracing an endwise movablevalve stem, an endwise sliding block fitting within the bore of thehandle and adapted to give endwise movement to the valve stem, saidsliding block being provided with a longitudinally arranged air assageand with a rigidly attached outward y extending stud, and said handlebeing provided with a longitudinal slot through which said stud extends,a hand lever extending lengthwise of said handle at one side of the sameand pivotally connected at one end with said handle by a transversepivot, the pivoted, end of said handle being engaged with the outwardlyextending stud on the sliding block, and a spring applied to hold thevalve in its closed position and the free end of the hand lever at adistance from the handle.

2. The combination with a pneumatic motor handle provided with a. boreor passage, of a throttle valve embracing an endwise movable valve stem,an endwise sliding block fitting within the bore of the handle andadapted to act endwise on said valve stem, said block being providedwith alongitudinally arranged air passage and with a.

studrigidly attached thereto and said handle being provided with alongitudinal slot through which said stud extends, and a hand lie leverpivotally supported upon the said handle and adapted at its pivoted endfor engageinent with the outwardly extending I .'-:tu l of the slidingblock, the said hand lever being provided with lateral arms which ex- Itend at opposite sides-'01 the handle and \\'lll('ll are pivotallyconnected with the same. i 3. The rolnliination with a. pneumatic inotorhandle provided with a hore or pass I of a throttle. valve embracing anendwise movable valve. stem, an eudwise. slidinghlnek fitting closely inthe bore of the handle and adapted to act endWise on the valve stem,said block being provided with a longitudinally arranged air passage andwith a stud I rigidly attached thereto, a sleeve surrounding the handle,said handle and sleeve being I provided with longitudinal slots throughwhich the said studs outwardly extend, a hand lever whichextendslengt-hwise of the handle, which is pivoted at one end to saidsleeve and engages at its pivotalend with Raid stud, and a spring actingon the valve stem to hold the valve normally closed and to maintain thefree end of the hand lever at a distaiuefroin the. handle. i

In testimony, thatl claim the foregoing a.' my invention I aflix mysignature in the presence of two wit-nesse, this 27th day of .\l a v l1909.

AXEL LE EDAHL. V Wl'ituesses: ll. lli'ii-iu, (l). llannnununn.

